Facebook is allowing its advertisers to work with third-party marketing firms to help better target their ads on its social network.

The change affects Facebook's custom audiences tool, which the company rolled out last year as a way for marketers to target people they've done business with in the past by using their phone number or email address.

Some businesses work with partners for their marketing efforts, so Facebook is expanding the audiences tool to let them work with Datalogix, Epsilon, Acxiom and BlueKai to better target their ads, Facebook announced Wednesday.

That means an auto dealer can incorporate information it gets from one of those third parties to build a Facebook campaign. Alternatively, Facebook will work with those third parties to create "targeting categories" for advertisers, such as "soda drinkers" or "people who browsed for a specific make/model on my website."

The changes come as Facebook faces increased pressure to monetize its services now that it's a public company. In particular, Facebook has struggled to sell advertisements displayed to mobile users, though it says it's making progress there.

The expanded audiences tool will still respect users' privacy, Facebook said. The marketing firms use a "privacy and data-protective matching process" intended to prevent them from accessing users' private information, it said.

The marketing changes will be rolled out in the coming weeks, starting in the U.S.